LOVE the art... unfortunately, I was unable to move and attack at the same time. Tried in Firefox, Chrome, and the downloaded version, but after pressing a movement key there was a two or three second cooldown before I could click again. I was working on a game of my own in Game Maker HTML5 where I had the exact same problem--not sure if it's just my computer or what. I'm on Windows 8.1, if that helps.